问题标题:
1/2+1/4+1/8+1/16+1/32+1/64的8种算法!
问题描述:
1/2+1/4+1/8+1/16+1/32+1/64的8种算法!
翟永顺回答:
1.1/2+1/4+1/8+1/16+1/32+1/64
=32/64+16/64+8/64+4/64+2/64+1/64
=(32+16+8+4+2+1)/64
=63/64
2.1/2+1/4+1/8+1/16+1/32+1/64
=(1-1/2)+(1/2-1/4)+(1/4-1/8)+(1/8-1/16)+(1/16-1/32)+(1/32-1/64)
=1-1/2+1/2-1/4+1/4-1/8+1/8-1/16+1/16-1/32+1/32-1/64
=1-1/64
=63/64
3.原式=1/2+1/4+1/8+1/16+1/32+1/64+1/64-1/64=1-1/64=63/64
4原式
=(32+16+8+4+2+1)/64
=63/64;
5、令m=1/2+1/4+1/8+1/16+1/32+1/64
两边同时乘2,得:
2m=1+1/2+1/4+1/8+...+1/32
两式相减,得:
m=1-1/64=63/646、作一矩形,(对不起,发不了图)对折得1/2,再对折得1/4,再对折得1/8,再对折得1/16,再对折得1/32,再对折得1/64,和为63/64
7、
这个是一个公比为1/2的等比数列求和
Sn=(a1-an×q)/(1-q)=(1/2-1/64×1/2)/(1-1/2)=63/64
8、原式=(1/2+1/4)+1/8+1/16+1/32+1/64
=(3/4+1/8)+1/16+1/32+1/64
=(7/8+1/16)+1/32+1/64
=...
=63/64
蒋宏回答:
有些看不懂,因为是小升初。。。
点击显示
数学推荐
热门数学推荐